“Sam could not remember much about the crash, until he found himself in the hospital bed with tubes in his mouth and nose and bottles of blood blood hanging on frames over his head. It had been a terrible nightmare of people shouting, blue lights flashing, stretchers, fire engines, the ambulance men lifting him out of the wrecked car.” You are reading fiction, not fact, but for “Sam” substitute “Norman” and for “car” substitute “rubble” – and you are suddenly in the real world: at Brighton in 1984, in the aftermath of the IRA bomb that injured the author and condemned his wife to a wheelchair for life.

“Write what you know,” Mark Twain said, and Lord Tebbit has taken his advice. The cover of “Ben’s Story,” a novel for childen – his first – makes the point. On the front is the silhouette of a boy in a wheelchair. On the back is a photograph of Lady Tebbit in hers. Lord Tebbit kneels at her side. A labrador sits beside him. “Ben’s Story” is the tale of a crippled boy (Sam) and a guide dog (Ben). It draws on the work of Canine Partners, the charity that provided Lady Tebbit with a real-life Ben – the dog in that photo. It reveals much about Norman Tebbit, the man as well as the politician.

The story pits Sam and Ben and their friends against the man who murdered Sam’s father, confined Sam to his chair, and now seeks to kill him too. In prose as well as politics, Lord Tebbit tends to see the world in black and white. “Ben’s Story” has heroes: Royal Marines, MI6 agents, charity workers, investigative journalists. (Lord Tebbit once worked for the Financial Times.) It also has villains: drug gangs, the Taliban, the IRA, the Russians. One of the latter turns out to be good – “the English treat their dogs like people and I’m afraid all too often we Russians treat people like dogs,” he says – but he is the exception who proves the rule.

This is all pretty much as it should be, but it is fair to say that the characters don’t surprise and the plot doesn’t twist: it seems to run on tram lines towards a confrontational end. Put like that, “Ben’s Story” ought not to work. And yet it does – very much so – because there is much more to Lord Tebbit, in art as well as life, than his fixity of outlook suggests. He was a Cabinet Minister so subtle in delivery as well as flinty in manner that his opponents often didn’t see him coming. Think, for example, of the way he gradually delivered trade union reform, or suddenly turned around the 1986 Conservative Party conference as Party Chairman.

This comes through in “Ben’s Story.” Its hero is unsympathetic to his step-father, for whom his mother deserted his father. But the former handles Sam with tact, affection and insight. It was Lord Tebbit’s opponents in his own party who mouthed the language of compassion. But the man himself has it, and that it isn’t worn on his sleeve makes it no less real. “What had happened had happened,” Sam thinks to himself about his injury. “That was that.” The author packs a mass of meaning into those three small words. Indeed, doing a lot with a little is his way. Lord Tebbit’s writing is marvellously economical. Not a word is wasted.

There is a self-sufficiency about his characters, too: his former Royal Marines are unmarried, living off meals kept heated in ovens or sandwiches pre-prepared for lunch. But the character in the story who perhaps interests its author most isn’t a human being at all. Lord Tebbit has thought deeply about dogs and humans and the relationship between them, as well as how the former see the world. There is a striking passage in which he describes how dogs can warn a person with epilepsy that he is about to have a fit, because they can somehow pick up the movement of electric currents in the brain. The shape and plot of the tale hangs on an imaginative re-working of that idea.

As the title says, it is Ben’s story and not Sam’s, but Lord Tebbit deals well with the daily challenges, the swings of mood, the everyday commonplaces that the able-bodied take for granted but which, for the severely disabled, can loom each day like a challenge. The relationship between the two, boy and dog, is warm, as such relationships can be – even when the dog in question is not, as Ben is, rather a special one. People can disappoint, but dogs are constant. Perhaps this is because, as Lord Tebbit suggests again and again in the book, the latter live for the present. “Ben did what dogs are good at doing. He simply put it to the back of his mind and thought about breakfast instead.”

Children’s books sometimes end with a sense of happily ever after – with “emotions recollected in tranquility”. Not this one. It ends sharply, even brutally, in a moment of Old Testament rather than New Testament morality: eye for eye, tooth for tooth. We are back with that taste for combat and confrontation that marked Lord Tebbit out as a politician – and still keeps him going in his eighties, battling all comers in his Daily Telegraph column. He brings to this book what he brings to politics: a bleak sense of perception and authority.

Though he never held even one of the great offices of state, he was one of the great shapers of the 1980s – second only, I think, to Margaret Thatcher herself. Like her words, his own helped to define the age: “I grew up in the 30s with an unemployed father. He didn’t riot; he got on his bike and looked for work and he kept looking ’til he found it.” As I read “Ben’s Story”, I found myself regretting that Norman Tebbit never succeeded her as Prime Minister. Why, given that my politics have never been his? Because if anyone deserved to, it was surely him.